"never Buy A Downward Firing Sub!" (1 Viewer)

...or at least that is what the salesman told me at a well known shop here in town. I was told that I needed an "active" sub because my room is too bright, with hardwood flooring, big windows and a high ceiling. He said that the 12" HSU I was considering would be really difficult to place in the room. He recommended a forward firing sub instead. I always thought that low frequency sound waves didn't reflect too badly off most surfaces!?! Are certain types of subs better suited for bright rooms? The room is 17'X 25' with 20 foot ceilings. Can any one 12" sub fill 10,000+ cubic feet?

No way jose.

For that much space you'll need some serious muscle if you want reference level bass with low distortion. Though I'm no expert on it...sounds like an IB would work most economically for a space like that if you own the home that it's in and don't mind a little DIY action.

-Dennis

Dennis, sorry to be such a green pea, but what does IB stand for?

IB stands for "Infinite Baffle"

Your house attic space, space under a raised floor, etc. becomes the subwoofer enclosure. Multiple drivers are mounted firing into your HT space from any large unused space in your house (a lot of people seem to like the attic). You can build one with a few drivers and some plate amps, and if done right, you can fill a huge room like yours with ridiculous amounts of bass. It all depends on your know-how with a little bit of carpentry, cutting holes in your walls/ ceiling and wiring some drivers. Many here and on other forums have reported big success with a variety of (some very creative) configurations.

IB Forums/ FAQ

Others should chime in, or simply do a search for "IB sub" in either this section or the DIY section for more information. The link above is a GREAT resource to get educated on how they work.

-Dennis

Hi Louis,

I guess IB stands for "Infinite Baffle", one way of pressing bass waves into the room if you like to dig holes into the house.

Having myself an "open house" situation with 10.044 cf space (the living room is open to kitchen and first floor galeria), I can tell from a quite nice sound coming from two PB12-Plus SVS Subs. That's just enough for me, and fits nicely as side tables to my living room furniture.

Even more bass would have come from a dual PB12-Plus/2, but I could not go that route a year ago as I was after the wooden finish of the single "Plus" range.
Wooden enclosures just popped up these days on PB12-Plus/2's.

To have plenty of everything that's needed for bass repro in such a large space...you'll need something like EIGHT SVS 16-46 cylinders--all down-firing, he, he, he--and perhaps even TWO B12-Plus/4s...

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."

Call me crazy but doesn't 17' * 25' * 20' = 8,500 cubic feet?

Forward firing vs downfiring should make little difference. Your salesperson is just trying to SELL.

That IS a pretty big room, however there's a person on here with a room larger than that and a single 25-31PCi is enough to give pant leg flapping ref levels without issue.


Yep, and factor in vaulted vs flat 20' ceilings and it is even slightly less...

Not picking a fight.................but no way a PCi could do anything near ref levels in a >5000^3ft. room. Of course every room is different, but I had a flat calibrated PC+ sub bottoming at -4 under ref in a 2800^3ft. room. On the Hsu side, you're looking at dual TN1220's or a PB12-Plus(or Ultra)/2 on the SVS side to fill that space.

Nothing to fight about, I was there. The room is ~20x30+ with high vaulted ceilings and the PCi did surprisingly well for that size room. I wouldn't say it if I hadn't heard it. The house is sitting on a big slab of concrete too, so that is likely a factor.

My room is slightly larger than 5K^3ft and the PB-10 does quite impressively also.

In very big rooms you have the advantage of room gain working very much in your favour.

Can a 12" Sub handle 10'000 sq feet??? you betcha!!

Here is my sub and I have 15000 sq feet roughly and it handles this room and then some upstairs and a few in the neighbors house as well...





Axiom Audio

If you truly feel 500 watts is not enough they have another model that puts out 600 watts

The old misunderstanding.

You wouldn't want ref-levels in a normal HT. "Reference level" does not mean "standard usable level". You would have to plug your ears.

And to answer the original question: down-firing subs are as good (soundwise) as any other design, as long as the design is done well (e.g. enough space between the bottom of the sub and the floor).


Cees

It's not the size of the room as much as it is how far you'll sit from the sub(s).

To exaggerate the point, put a mic 6" from the sub and it'll register 'ref levels' of SPL regardless of the size of the room.

The only difference between and front firing and down firing sub (noting Cees' point that we assume a well done design of each type) is that with a front firing sub, you'll hear the direct radiated sound before any reflected sound, whereas with the down firing sub you'll only hear reflected sound.

I'm very curious to know what front firing sub the salesman recommended??

Hi Ya Dave ... Good to see you posting again !

Alright, now that you guys are done beating me up...........I was referring directly to the capability of playing at reference levels, not that you HAD to. But, if John says he witnessed it, so be it. Sorry for causing a stir.

Back-at-cha, Craig...and Thank You Very Much.

Wayne,

CRAP! The fight's over and I didn't get to beat you at all. (I'm still with you on this one, BTW...Shhhhhhh).

Thanks for all the feedback. Sorry if 10,00 sq ft was a little generous on the room space. The fellows at Axiom told me I had over 10,000, and I never did the math myself.

Nobody's beating anyone.... The guy is a member of this forum, I'll e-mail him and see if he can give some numbers, because I know he's done measurements.

As Cees notes also, I would never sit and listen at ref level. In my apartment, the PB-10 at 50% gain starts vibrating everything before I reach ref levels. If Phil isn't hitting ref levels, then it is still more than adequate levels of bass. I'm sure his seating position relative to the sub, size and shape of the room etc... are all factors. I was sitting 10' away from the sub and it was flapping my pant leg - the first time I had a sub do that.

What kinda pants where they? They sound light and comfortable and since my PB2+ can't do it with my current wardrobe, I might have to upgrade.........